Parse string using bash

StrongIce · 08-06-2012, 06:26 AM

Hi,

Linux newbie here trying to create a simple bash verification script.
I need help to parse this tring and put the date in a variable.
This line is from the 3rd line of a file.

VARIABLE_DATE 080612 08/06/2012 14:13:10

There are more spaces in between the values but I just need the
date 080612 so I can confirm it with the current system date
VDATE=`date '+%m%d%y'`.

Would greatly appreciate if someone could help.

rosehosting.com · 08-06-2012, 06:54 AM

Quote:

Originally Posted by StrongIce

Hi,

Linux newbie here trying to create a simple bash verification script.
I need help to parse this tring and put the date in a variable.
This line is from the 3rd line of a file.

VARIABLE_DATE 080612 08/06/2012 14:13:10

There are more spaces in between the values but I just need the
date 080612 so I can confirm it with the current system date
VDATE=`date '+%m%d%y'`.

Would greatly appreciate if someone could help.

Hi, something like the following could work for you to only get the date which in your case is '080612'.

Code:

# TEST='VARIABLE_DATE      080612         08/06/2012        14:13:10'
# echo ${TEST} | grep -Eo '[[:space:]]+[0-9]{6}[[:space:]]' | grep -Eo [0-9]{6}
080612

it will get the date only no matter how many spaces are there in between the values.

hope that helps

grail · 08-06-2012, 10:23 AM

Well as you asked for bash, here are 2 ways:

Code:

str='VARIABLE_DATE 080612 08/06/2012 14:13:10'

regex='^[^ ]* ([^ ]*)'

[[ $str =~ $regex ]] && echo ${BASH_REMATCH[1]}

str2=${str#* }
str2=${str2%% *}

echo $str2

chrism01 · 08-06-2012, 07:06 PM

Depends what you mean by 'using bash'; strictly bash fns only, or are you allowed to use/call eg awk ?

Code:

d=$(echo "VARIABLE_DATE   080612   08/06/2012 14:13:10 "|awk '{print $2}')
echo $d
080612

StrongIce · 08-07-2012, 03:46 AM

Thank you all for the suggestions. I will try them all out and let you know the results though I know that
all of them should be working fine!